You don't mention what lens you're currently using. Assuming it's the 18-55 kit lens, it's no wonder the zoom isn't great. The 55-200 is a budget lens so ultimately you get what you pay for, but it is a superb investment for the money. It'll produce crisp, punchy images (colour can be muddy at times though) and has a useful focal length. I find Canon's budget lenses tend to be a lot sharper than those made by third parties such as Tamron and Sigma. Although I've never owned or used the lens in question, I know people who have and also have experience with other budget Canon lenses, i.e. 75-300 USM
III. Remember, the equipment is only as good as its operator, and if you're competent you can get some fantastic quality photo's out of even the most basic kit.